Lightning arrester



J. T. GREENE LIGHTNING ARRESTER April 15 1924.

Filed April 9, 1919 2 Sheets-Sheet 2 QAM @5% Patented Apr. 15,

UNITED STATES PATENT OFFICE.'

JOHN T. G OF TOLEDO, OMO, ABSIGNOB `NATIONAL mmc SPE'- CIALTY COMPANY,Ol' TOLEO, OHIO, A. CORPORATION OF OHIO.

` Home amm applicano inea- Apru s, 191s. sex-mig. naar.

To all whom it may concern:

Be it known that I, JOHN T. GREENE, a citizen of the United States,residing at Toledo, in the county of Lucas and State of 6 Ohio, haveinvented certain new and useful Improvements in Lightning Arresters, ofwhlch the following is a s iication.

My'invention relates to evices, commonly called lightning arresters, forlprotecting electrical a aratus from the estructive effects of lghpotential charges due to lightni crosses with high power wires, and the'ke.

More particularly my invention relates to a vacuum lightning arrester ofthe cartridge type, that is, a device comprising an evacuated tubepreferably of glass with the leading- 'in line and ground wlres for theelectrodes extendin into the tube. Heretofore in devices of t is typeparticularly those em loying a fragile tube, the two line wires ave beenrun in through one end of the tube and connected to their respectiveelectrodes and the ground wire has been run in through the other end ofthe tube and connected to its electrode.

The princi al object of my invention is to provide a liglitnin arresterof the vacuum type employlng a ragile tube, for example, of glass inwhich any tendency for the ine Wires to short circuit will be reduced toa minimum and to this end my inventionA aimsito provide an arrester ofthis type in which the three Wires, namely, the two line and groundwires enter the evacuated tube at three different points, each being asubstantial distance from the others, and in its preferred form one linewire is run in through one end' of the tube and connected toitselectrode and the other line wire is run in throu h the other end of thetube and connecte to its electrode, the ground wire being run in throughthe side of the tube and connected to its electrode.

lli The glass tube in an arrester of the cartridge type is ordinarilysupported at opposite ends in spring cllss or the like. Apparently thegreat heat evelopedby a discharge between the electrodes tends to i0soften the glass at the middle of the tube tov a certain extent. Thestresses develged on the rarefied gas when a discharge es place alsoapto have a destructive eect upon the adjacent part of the tube. For these'and possibly other reasons the glass tube in a device of this ty has atendency yto sag or break in the rmddle. A'further object of myinvention is to provide means which will rigidify and stren henthe tubeferred embodiments, in the accompanying drawings, wherein- Fig. 1 is arester embodymg the principles of my invention.

Fig. 2 is a side elevational view.

whic the line wires are attached.

Fig. 4 is a longitudinal sectional view taken along the line 4-4 of Fig.1.

Fig. 5 is a longitudinal sectional view taken along the line 5-5 of Fi2; and

Fig. 6 is a transverse sectiona view taken alon the line 6-6 of Fig. 2.

Li e characters of reference desi ate like parts in the several figuresof the rawings.

The base joriblock 10 is made of porcelain or other suitable materialand is provided with a binding post 11 for the ground wire 12 and withbinding posts 13 and 14 for the respective line wires 15 and 16. Y

The evacuated tube 17 is preferably made vof glass and is provided atopposite ends with the inturned stems 18 and 19. Secured to the stem 18,preferably by a body of asbestos cement 20, is a porcelain base member21 formed with a pair of lugs 22. A line Wire electrode 23 is secured tothe base member 21, preferably by a body of asbestos cement, on t eouter side of one of the lugs 22. A leading-in wire 24 extends from ametal ca 25, surrounding the end of the tube, an is embedded in andelectrically connected to the electrode 23. This end of the tube issupported in a. spring clip 26 lan view of a lightning ar- Fi 3 is anelevational view of the end tosecured to theblock 10 by a screw 27 whichis electrically connected to binding post 13 by a wire 28.

A base member 29 formed with a pair of lugs 30, is secured by a body ofasbestos cement'3l to the stem 19 at the other end of the tube. A linewire electrode 32 1s secured to the base member 29, preferably by a bodyof asbestos cement, on the outer side of one of the lu 30 but on theside o posite that side of t e lug 22 to which the e ectrode 23isvsecured. A leading-in wire 33 extends from a metal cap 34, surroundinthis end of the tube, and is embedded in an electrically connected tothe electrode .32. This end of the tube is supported in a sprmg clip 35secured to the block 10 by a screw 36 which is electrically connected tothe binding post 14 by a wire 37.

A ground wire electrode 38 is secured to 4the base member 21, preferablyby a body of asbestos cement, between the lugs 22, 22. A leading-in wire39 extends from a metallic band 40, surrounding the middle of the tube,and is embedded in and electrically connected to the 'electrode 38. Whenthe ends of the tube are pressed down into the spring clips 26 and 35the band 40 resses firmly against a s ring terminal mem r 41 secured tothe bloc 10 by a screw 42 which is electrically connected to the bindingpost 1]. by a wire 43. vOne end of the band 40 is provided with atransverse slot 44 and the other end is provided with a tongue 45 whichis adapted to slip through the slot 44 and be bent over after the bandhas been pressed closely around the tube. Preferably the band is securedto the tube by a layer of suitable cement 46. Preferably the respectivespring clips 26 and 35 are rovided with lugs 26 and 35* to prevent tlielongitudinal displacement of the arrester in this direction in case thearrester is positioned verticall It willI be apparent from Fig. 5 of thedrawings and the foregoing description that the electrodes are arrangein an interlocking relationship between the respective lugs provided onthe base members 2l and 29. This arrangement in connection with themetallic band around the tube bearing against the spring clipstrengthens and rigidilies the entire device against and tendency to sagwhen the tube is heated, or to break because of vibration or othercauses when in service, or because of rough handling in shipment. Inmanufacturing the device, each base member may be united with its stem,the electrode secured to the base member, and the leading-in wire sealedthrough the stem. The ground electrode may be secured to either basemember and the leading-in wire sealed through the side of the tube and-connected to the metallic band. The structures may then be placed inthe interlocked relationship described and the stems sealed to the tube.

It will be apparent from the foregoing description that an tendency ofthe line wires to short circuit is reduced to a minimum. Although Irefer to have the two lines discharge into t e evacuated tube from eachend as described, thus maintaining constant equal distribution andbalance on both sides of the line to be protected, it will. beunderstood that both line wires may run into the tube through one endand the ground wire be connected to the band and run into the tubethrough the side, or, if desired, any other similar arrangement may beemployed as, for example, the ground wire may be run into the tubethrough one end, one of the line Wires through the other end and theother line wire beconnected to band and run into the tube through the sie.

It. will be apparent to those skilled in the art that furthermodifications might be made without departure from the principle of theinvention. Therefore, I do not wish to be understood as limiting theinvention to the precise constructions, arrangements and devices, exceptonly so far as certain of the claims are specifically so limited.

claim:

1. A lightning arrester comprising a base, an exhausted tube mounted onsaid base and having hollow inturned stems at opposite ends, lineelectrodes supported on said stems in fixed spaced relation to eachother, line wires entering the tube through said inturned stems at asubstantial distance from each other and connected to said elec-- modes,a ground electrode disposed between said line electrodes and in fixedspaced relation thereto to provide spark gaps, the ground leading inwire entering said tube through one side thereof and at a substantialdistance from each of said line wires and being connected to said groundelectrode, a metallic band around said tube in close proximity to saidspark ga serving to strengthen and reinforce the tilise against internalpressure and to which said ground leading-in wire is connected, and aspring terminal member mounted on said base and bearing against Saidband so as to serve both'as an electrical connection between said bandand the ground wire and as a support to prevent sagging of theintermediate portion of the tube when the latter is heated by anelectrical spark passing across one of said spark gaps.

2. A lightning arrester comprising a base, an evacuated fragile tube,line electrodes electrically connected with line wires and supported infixed spaced relation to each ot er near the middle point of said tube,a ground electrode supported between the line electrodes and in fixedspaced relation thereto so as to provide spark gaps, a ground leading-inWire sealed through the side of the tube and connected to the groundelec- 5 trode, a metallic band connected to said ground leading-in wireand extending around the tube in close proximity to said spark gaps toreinforce the tube against internal pressures, and a ground terminalmember mounted on said base and bearin 10 against said band to supportthe same and prevent sagging of the tube when the latter is heated by anelectrical spark passing across one of said spark gaps.

JOHN T. GREENE.

